轴向放置的轴向磁化多环永磁轴承径向磁力研究

Research on the Radial Magnetic Force of Axial Placement and Axial Magnetization Multiannul-shaped Permanent Magnetic Bearings

针对轴向放置的轴向磁化双环永磁轴承径向磁力偏小以及磁力数值计算复杂等问题,设计了能充分利用磁能、具有更大径向磁力的轴向放置的轴向磁化多环永磁轴承。分析了磁环气隙磁导,结合稀土永磁材料特性、磁通连续原理和线性叠加原理,用虚位移法得到了该永磁轴承径向磁力解析模型。经由三坐标立式铣床和三轴测力仪改装的实验台测试验证,模型计算值和实验值基本吻合。

Aiming at small magnetic force and the complexity of magnetic force numeral calculation for previous research of radial magnetic force model on APAM （axial placement and axial magnetization） hi-annular-shaped PMB（permanent magnetic bearings）, the new construction of APAM multi-annular -shaped PMB was designed,which can make good use of magnetic energy and have greater radial magnetic force. Based on analysis of the gap magnetic conductance of multiannular-shaped PMB, connected with rare earth permanent material property and the principle of magnetic-flux equivalency in flux paths as well as linearity adding, this paper adopted the differential coefficient of magnetic energy to virtual displacement method to derive a magnetic force analytical calculation formula of APAM multi-annular-shaped PMB. This formula indicates that the radial magnetic force of APAM multi-annular-shaped PMB is in positive proportion to the second power of residual magnetism induction density,and that the radial magnetic force increases with an increment in the magnetic annular radial size, average radius, the number of permanent magnetic annular and total magnetic conductance of magnetic circuit, and that the radial magnetic force decreases with an increment in the axial and radial gap. Test validation employed experimental device refitted by triaxial vertical milling machine and triaxial ergometer,the model calculation values are basically in agreement with those actually-measured.